Digital Commons Network^™

Habitat Selection By Desert Carnivores: How Water, Intraguild Predation, And Prey Impact Animal Space Use, Nadine A. Pershyn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Across North America large carnivores have lost nearly half of their historic range, creating openings for smaller (< 15 kg) carnivores to take over their ecological roles. Coyotes (Canis latrans) have seen a significant range expansion, including into arid deserts. It was believed that the addition of artificial water sources by humans allowed coyotes to expand into desert ecosystems where they were previously unable to survive. The kit fox (Vulpes macrotis) is a small, desert-adapted carnivore with declining populations that faces threats from coyotes of intraguild predation. This is when carnivores compete over the same prey, and the larger carnivore (intraguild predator) kills the smaller carnivore (intraguild …

An Evaluation Of The Food Web Dynamics And Predator Prey Interactions In Scofield Reservoir, Lisa K. Winters

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Reservoirs are artificial, dynamic, and highly manipulated systems, where the appearance of either intentionally or unintentionally introduced species may disrupt interactions within an already complex food web. In some situations, a top predator fish may be stocked as a biological control agent, if these fish-eating predators monopolize on the nuisance and unwelcome prey. Scofield Reservoir, Utah has historically been an extremely popular blue-ribbon fishery. However, a recent decrease in rainbow trout catch and increase in the minnow, Utah chub, have made it difficult to find a balance between providing the public with a trophy sport fishery and maintaining an ecologically …

Spider Community Composition And Structure In A Shrub-Steppe Ecosystem: The Effects Of Prey Availability And Shrub Architecture, Lori R. Spears

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Habitat structure is cited as an important factor influencing organisms, but few studies investigate whether habitat structure interacts with other environmental variables to affect community dynamics. The purpose of this study was to determine, using field experiments, the importance of prey availability and shrub architecture on a spider community in northern Utah, USA. We were also interested in determining whether surrounding shrub architectures influence spider and prey responses.

Our results suggest that spider distribution, abundance, and biodiversity are influenced by shrub architecture. Shrub architecture influenced spiders both directly and indirectly via associated changes in prey availability. Spiders were also directly …

The Influence Of Forest Fragmentation And Landscape Pattern On American Martens And Their Prey, Christina D. Hargis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Habitat fragmentation occurs when large tracts of an orginal habitat are replaced by smaller patches of two or more habitat types, largely through human activities. I studied the behavior of six measures of landscape pattern that seemed appropriate for quantifying fragmentation, and used these measures to investigate the effects of forest fragmentation on American martens (Martes americana) and their prey. The measures I selected were edge density, contagion, mean nearest neighbor distance between patches, mean proximity index, perimeter-area fractal dimension, and mass fractal dimension. To test the behavior of these measures with a variety of landscape patterns, I …